Abstract
Studies on evolutionary convergences can provide important insights for understanding the factors that influence evolution. To contribute to the understanding of the patterns and processes involved in metazoan evolution and diversification in the marine environment, this study aims to investigate evolutionary convergences potentially associated with marine habitat shifts, using the class Cephalopoda as a model group. To achieve the proposed goal, we will investigate cephalopod sperm transfer mechanisms, some of which have been proposed as potentially convergent and correlated with habitat. First, organs and structures responsible for sperm transfer will be subject of functional morphology studies, aiming at the understanding of the mechanisms involved in spermatophore transfer, implantation, and storage. These analyses will include histological and electron microscopy techniques, and in vitro experimentation. This study aims also to provide a reasonable bulk of morphological data related to cephalopod reproductive strategies to allow the identification of putative homologous structures. Ancestral states for these characters will be reconstructed to attempt to identify characters that have arisen via convergent evolution. These will then be assessed for correlation with habitat, also using a phylogenetic context. Based on these results, adaptive hypotheses will then be inferred, tested and discussed. (AU)